SM-MRAS based sensorless MPPT control for dual power flow wind energy conversion system

This paper presents a novel sensorless maximum power point tracking (MPPT) algorithm for the new dual power flow (DPF) wind energy conversion system (WECS) which is based on electrical variable transmission (EVT) machine. The optimum current given (OCG) MPPT strategy is proposed for the outer rotor of the EVT machine. The algorithm works in two stages: In the first stage, the relationship between the loss torque and the rotor speed of the outer rotor is estimated. In the second stage, the maximum power point (MPP) is tracked by giving the optimum current considering the loss torque. For cost and reliability consideration, the novel sliding mode (SM) model reference adaptive system (MRAS) observers are adopted to estimate the outer rotor speed and position. The proposed SM-MRAS observers are based on the calculations with no need of the PI loop that exists in the classical MRAS observers. The effectiveness of the proposed SM-MRAS based sensorless OCG MPPT algorithm for the DPF-WECS is verified by the experimental results.